The present invention relates to reclosable packaging and, in particular, to an apparatus for horizontally forming, filling and sealing such packages to loosely fit about a packaged product.
Horizontal form, fill and seal (HFFS) machines are commonly used for packaging block-shaped products such as chunks of cheese, cheese slices or various products that are contained in a tray such as cookies and crackers. The package is formed of a flat sheet of plastic film onto which the product is deposited. One or both side portions of the sheet are wrapped over the product, the sheet side edges are sealed together and transverse seals are formed to complete the package about the product. A zipper may be provided for the package between the sheet edges or in a fold formed in the film in order to render the package reclosable after it is initially opened through the zipper. U.S. Pat. Nos. 4,589,145; 5,247,781 and 6,138,436 are representative of such prior art HFFS machines.
The packages formed on such machines are generally tightly pulled over the product during the wrapping operation for package aesthetics and in order to maintain constant width for the final packages. That is, if the film is not pulled at least semi-tight over the product, the width of the final packages tends to vary from package to package. Further, unless the film is pulled at least semi-tight the film may wrinkle during the package formation. These may cause consumer acceptance problems as well as difficulties in packing the packaged product. However, for certain applications, it may be desirable not to have the packaging film tight against the product. For example, a loose package permits easier removal of the package contents and facilitates returning product to the package. Also, where the package is to be provided with a fitment such as a spout or a zipper and, particularly with a slider activated zipper, a tight fit between the package and product may place undo stress on the package and interfere with the operation of the zipper. Also, where a tamper evident seal is provided inboard of the zipper, the consumer may find it difficult to rupture the seal when the product is tight against the seal.